Priming of explosives.



LOUIS LHEURE, OF PARIS, FRANCE.

PRIMING OF EXPLOSIVES.

Specification of Letters Patent.

Patented Oct. 22, 1 907.

Application filed January 27, 1905. Serial No. 242,944.

To all whom it may concern:

Be it known that 1, Louis LHEURE, a citizen of France, residing atParis, France, have invented certain new and useful Improvements in thePriming of Expljosives, of which the following is a specification.

This invention relates to the priming of explosives.

In the employment of explosives it is diflicult to reconcile safety ofmanipulation with effective action in the shot-hole. If the explosivesdetonate easily their employment may give rise to accidents whereas ifthey are on the contrary only slightly sensitive their detonation isoften incomplete, their effects are diminished, and the presence ofsmall unexploded pieces in the debris or fallen material sets up asource of subsequent danger.

The arrangement of priming which forms the object of the presentinvention permits without increasing the danger of manipulation: 1. Ofinsuring the complete detonation of explosives of slight sensitiveness.2. Of increasing the bursting effects of all kinds of explosives. 3. Ofremoving (at will) to the exterior of the shot-hole the detonator offulminate of mercury, the presence of which in the charge constitutes apermanent cause of dangerduring tamping or ramming and especially incases of a miss-fire.

The improved primer is shown by way of example -.in the accompanyingdrawings'in a vertical section The improved primer consists of adetonating fuses of comparatively .small diameter which containstrinitrotoluene or trinitrobenzene and which fuse is emranged at'tdrawing.

The detonator 0 contains fulminate of mercury and it is connected withfuse a through a suitable detonating tube d of smaller diameter than thefuse a, when it is not placed at the top-end of the charge as shown inFig. 2 but outside the shot-hole, as shown in Figs. 1 and 3. In thiscase the end of detonating tube at is clamped in at the upperend of thefuse, as shown in the drawings.

The trials made have shown that the same charge of powder placed underthe same conditions has produced a cavity of 80 cubic decimeters when ithas been primed as described with the improved detonating tube, whereasit has given only a cavity of insignificant volume when the priming hasbeen by means of a Bickiord fuse. There is therefore attained by theimproved primer a considerable increase in the burst ing effects of thepowder.

With explosives having a base of chlorate of potash or of nitrate ofammonia say for safety, analogous effects havebeen obtained and it hasbeen possible to insure the complete detonation of these explosives evenwhen very compressed. Other trials have shown that this same primerarrangement allows of insuring the complete detonation of blastinggelatin by binding the fuse on to the cartridges (as shown in Fig. 3)without any necessity for fitting the connection of the detonator intothe cartridges. The same primer arrangement will serve equally to betterinsure the detonation of other dynamite compositions.

This improved primer may be advantageously used for the priming ofcharges of explosives consisting of mixtures or compounds which havehitherto been considered as non-explosive, in particular nitrate ofammonia.

What I claim as my invention'and desire to secure by Letters Patent is:t

An improved primer consisting of a detonating fuse of small diameterembedded in the entire length of the charge I and a separate detonatorof suitable composition connected Witnesses JOHN BAKER, ALFRED FREY.

LOUIS LHEURE. H

